Australia’s current energy policies and plans are a recipe for triple failure: rising costs, falling reliability and growing environmental footprints. Wind and solar power plus battery and pumped-hydro storage have roles in a zero-emissions power system, but they cannot do it alone. A net-zero goal requires all options, including carbon capture and storage and nuclear energy. Many of our fellow engineers agree. If only they weren’t too afraid to say so.

The Australian government policy is for 82 per cent renewable electricity generation by 2030, or about 70 per cent if we exclude the historical hydro energy assets. The Australian Energy Market Operator (AEMO) has published a report on a 100 per cent renewable electricity system.

A “positive experience”: the Darlington Nuclear Generating Station, in Clarington, Ontario. Credit: Christopher Katsarov

Could Australia run its electricity systems on 80 or 100 per cent renewable energy? No, and it would be foolish to try. Proponents of this unproven alternative system should bear the burden of proof. Since a negative cannot be proven, we offer a non-technical explanation and summarise the weight of evidence for our view.

Such a system would be very expensive, insecure and heavily weather-dependent. It would have vast land footprints and dangerously low energy diversity. And it would be profoundly inequitable. We find that we are far from alone in these judgments.

Veteran engineers generally tend to share our view. Worryingly, many others are afraid to say so, perhaps for fear of being unfashionable, missing out on a grant, offending a client, being trolled on LinkedIn, overlooked for promotion, or dismissed from a job.

But aren’t wind and solar the cheapest form of energy? Isn’t nuclear high cost? Not when we consider value: with zero emissions, nuclear capacity in a system underpins always-available power at a predictable, affordable price where it counts: at the wall socket. This finding transcends the various real-world uncertainties for all technologies and projects.

Contrasting relevant examples are instructive. Germany’s failing Energiewende, or “energy turnaround”, is a cautionary case. Ontario’s well-managed nuclear-for-coal “fuel switch” has been a positive experience.

Every net zero emissions plan needs some carbon capture and sequestration; like it or not, CCS provides the “net” in net zero. If Australia’s current nuclear energy bans and net zero pledges both remain, much larger and more extensive CCS will be demanded. Denying the technology to abate emissions from coal or gas is a contradictory policy.